During patent prosecution, Examiners often liberally apply the broadest reasonable interpretation standard in rejecting claims.  When responding to these rejections, it is important to remember that there are limits to an Examiner’s broadest reasonable interpretation.  In Ex parte Wilhelm Heine (“Heine”), the Patent Trial and Appeal Board (“PTAB”) rejected the Examiner’s unreasonable claim construction stating that “‘[t]he correct inquiry in giving a claim term its broadest reasonable interpretation in light of the specification is not whether the specification proscribes or precludes some broad reading of the claim term adopted by the examiner.’”  Appl. No. 14/076,456, Decision on Appeal (Sept. 25, 2019) (hereinafter “Heine”), at 6 (quoting In re Smith Int’l, Inc., 871 F.3d 1375, 1382–83 (Fed. Cir. 2017)).  Instead, Examiners need to rely on a claim interpretation that is consistent with the core, inventive concept of the invention.  Id.

The application at issue was U.S. Patent Application No. 14/076,456 directed to methods and an apparatus for membrane separations of complex flow media compositions.  According to the specification, the traditional approach was to use multiple, successive separation mechanisms to isolate products within complex compositions that may contain multiple liquid phase components and possibly gaseous components.  The specification disclosed a single separation apparatus and method that advantageously achieved the separation of the complex flow media compositions.

During prosecution, the Examiner repeatedly rejected the claims over the prior art by construing an undefined claim term to mean something that was inconsistent with the Applicant’s specification.  While the Examiner’s claim construction allowed for mapping of the claim term onto multiple separation operations found within the prior art, that claim construction was inconsistent with the core, inventive concept of a single separation apparatus and method.  The PTAB reversed the Examiner and further stated “that the Examiner’s articulated reasoning is not based on some rational underpinning to support a conclusion that a person skill in the relevant art would have combined the references in the manner claimed.”  Id. (emphasis in original).

In view of the guidance from Heine, practitioners may want to keep the following in mind.  In arguing against an Examiner’s broadest reasonable interpretation, it may be beneficial to remind the Examiner that the inquiry should not be made in isolation, but needs to be made in accord with the specification.  Just because a claim term may not be explicitly defined in the specification, an Examiner cannot simply set forth any claim construction he or she desires.

Heine also reminds us of the benefit of defining claim terms within the specification during drafting.  By taking the time to define and to explain claim terminology, an applicant can later point to a specific portion of the specification in support of arguments to refute an initial rejection by an Examiner.  Support, even if just in a single paragraph, focuses the argument and avoids the need for an Examiner to synthesize and understand the entire specification just to interpret the claim terms.  

The timing of Heine is also informative.  After filing the Notice of Appeal, the PTAB decided Heine just over two years later.  If an Applicant can wait that two-year period, appealing may be an option when dealing with an Examiner that maintains a claim construction that is overbroad -- especially if the disputed claim term is essential to the core invention.